1. Field of the Invention
The invention relates to optical diagnosis, in particular, to a large area optical diagnosis apparatus and operating method thereof using re-designed light path structure and signal analysis unit to achieve the effect of synchronous multi-point optical coherence tomography (OCT) diagnosis.
2. Description of the Prior Art
In recent years, with the continuous progress of optical diagnosis technology, the optical image scan technology provides a non-invasive way to understand the composition and structure of the tissue of the object to be diagnosed. Because it has features of rapid and non-invasive, it is widely used in many regions, especially in medical diagnosis region. When the light is emitted into the tissue structure, with the various media in different depths, the light absorption characteristic and scattering characteristic will be also changed accordingly. And, the optical image scan technology uses different optical methods to obtain the data carried by the scattered photons in the tissue to generate high-resolution image.
In general, the medical imaging technology is used to measure the physical characteristic change generated after the physical field source is provided to the tissue and convert it into visual images. By doing so, the abnormal state of the tissue structure can be clinically judged in a qualitative and quantitative way and dynamic functional assessment can be done to provide rapid and correct diagnosis and treatment of disease, therefore, quality of medical care can be enhanced. In the trend of the medical imaging technology, the non-ionizing energy field source is used to measure and imaging in a non-invasive way to have high space resolution and contract resolution, and real-time image displaying.
In the known medical imaging technologies, a medical imaging technology called optical coherence tomography (OCT) is used to measure the coherence property of the scattering light field strength in the depth direction of the tissue and further generate 2-D or 3-D images via the low coherence light source and the measurement structure of change optical path difference interferometer. Since the OCT medical imaging technology can meet the developing requirements of the trend of the medical imaging technology, the OCT medical imaging technology is widely researched and used in many application regions.
In practical applications, because the OCT medical imaging technology has advantages of high resolution, high sensitivity, non-ionizing energy field source, low cost, and it can measure the cross-sectional structure of the tissue in the object to be diagnosed and the flow-rate distribution diagram. Therefore, it can provide image with micro level resolution to help the diagnosis of tissue disease and the positioning of the cell structure, such as the retinal of eye-ball.
Please refer to FIG. 1. FIG. 1 illustrates a schematic figure of the basic structure of the conventional time-domain OCT diagnosis apparatus. In order to generate the light path difference between the reference end and the object to be diagnosed end, the OCT diagnosis apparatus needs not only some complicated optical components, but also a shifting mechanical structure to generate the light path difference.
In addition, as shown in FIG. 1, the conventional OCT diagnosis apparatus 1 includes a light source 10, a light coupling unit 12, a reflection mirror 14, an object to be diagnosed 16, a light sensing unit 17, and a data processing unit 18. The conventional OCT diagnosis apparatus 1 changes the position of the reflection mirror 14 (movement parallel to z-direction or rotation) to obtain different light path difference, and obtains sensing result of the object to be diagnosed 16 in the depth direction (z-direction) through Michelson interference effect.
Afterward, another frequency-domain OCT diagnosis apparatus is developed. The frequency-domain OCT diagnosis apparatus includes specially designed sensing/receiving unit to obtain the interference comparing result between the reference signal and the reflected signals from different depths of the object to be diagnosed. However, no matter the above-mentioned time-domain or frequency-domain OCT diagnosis apparatus, a galvo-mirror is needed in the light path to change diagnosis points, and the structure of the OCT diagnosis apparatus will become complicated. In addition, because the time-domain and frequency-domain OCT diagnosis apparatus can only diagnose the diagnosis points one by one, it fails to perform a large-area diagnosis at the same time, so it is time-consuming and inconvenient, and has limitations in practical applications.
Therefore, the invention provides a large area optical diagnosis apparatus and operating method thereof to solve the above-mentioned problems.